backup: add backupts file as lock

cmd/backup.go

@@ -2,6 +2,7 @@ package cmd
 
 import (
 	"context"
+	"fmt"
 
 	"github.com/pingcap/errors"
 	"github.com/pingcap/log"
@@ -108,6 +109,11 @@ func runBackup(flagSet *pflag.FlagSet, cmdName, db, table string) error {
 		return err
 	}
 
+	err = client.SaveBackupTS(ctx, backupTS)
+	if err != nil {
+		return err
+	}
+
 	defer summary.Summary(cmdName)
 
 	ranges, backupSchemas, err := backup.BuildBackupRangeAndSchema(
@@ -170,6 +176,12 @@ func runBackup(flagSet *pflag.FlagSet, cmdName, db, table string) error {
 	if err != nil {
 		return err
 	}
+
+	content, err := client.GetBackupTS(ctx)
+	if err != nil {
+		return err
+	}
+	fmt.Println(string(content))
 	return nil
 }
 

pkg/backup/client.go

@@ -120,6 +120,35 @@ func (bc *Client) SetStorage(ctx context.Context, backend *backup.StorageBackend
 	return nil
 }
 
+// SaveBackupTS saves the backup ts at the given path.
+func (bc *Client) SaveBackupTS(ctx context.Context, backupTS uint64) error {
+	if exists, _ := bc.storage.FileExists(ctx, utils.TSFile); exists {
+		return errors.New("this storage has backup file, consider clear this storage or change to new one")
+	}
+	backendURL := storage.FormatBackendURL(bc.backend)
+
+	log.Info("save backup ts", zap.Stringer("path", &backendURL))
+	type fileContent struct {
+		StartedAt string `json:"started_at"`
+		BackupTS  uint64 `json:"backup_ts"`
+	}
+	f := &fileContent{
+		StartedAt: time.Now().Format("2006-01-02 15:04:05"),
+		BackupTS:  backupTS,
+	}
+	fileBytes, err := json.MarshalIndent(f, "", "\t")
+	if err != nil {
+		return err
+	}
+
+	return bc.storage.Write(ctx, utils.TSFile, fileBytes)
+}
+
+// GetBackupTS get the backup ts from given path.
+func (bc *Client) GetBackupTS(ctx context.Context) ([]byte, error) {
+	return bc.storage.Read(ctx, utils.TSFile)
+}
+
 // SaveBackupMeta saves the current backup meta at the given path.
 func (bc *Client) SaveBackupMeta(ctx context.Context) error {
 	backupMetaData, err := proto.Marshal(&bc.backupMeta)

pkg/utils/schema.go

@@ -17,6 +17,8 @@ import (
 const (
 	// MetaFile represents file name
 	MetaFile = "backupmeta"
+	// TSFile represents backup ts file, it generated before backup
+	TSFile = "backupts"
 	// MetaJSONFile represents backup meta json file name
 	MetaJSONFile = "backupmeta.json"
 )